"These are just three examples of governmental action antithetical to freedom of speech and association for which Attorney General Sessions is either closely affiliated or directly responsible", the professors wrote in the letter. "This is not the great tradition of America".

Sessions in his speech also railed against the fierce protests that have recently erupted following the invitation of controversial speakers - particularly at UC Berkeley, where administrators reportedly spent $800,000 on security for a free speech rally organized by the far-right speaker Milo Yiannopoulos. The university sent out a campus-wide email to students and staff prior to the speech, offering counseling services to those offended by Shapiro's speech.

Sessions' remarks come at a divisive time on college campuses.

At one point, the attorney general compared mask-wearing activists who were attempting to shut down an event at Middlebury College to members of the the Ku Klux Klan, even though one could argue they were exercising their First Amendment rights.

"What we have here today is a number of students who wish they could have attended the event to ask challenging questions", said Waweru, who was sporting a "Black Lawyers Matter" T-shirt.

Sessions announced that the Justice Department "will enforce federal law, defend free speech and protect students' free expression from whatever end of the political spectrum it may come".

Phillips, who co-authored the release, said students believed the list was carefully crafted to ensure a sympathetic audience because it was limited to those who had an affiliation "either with this conservative center or this conservative professor". "The American heritage of law. But, to quote James Baldwin, 'exactly for this reason, I insist on the right to criticize her perpetually'".

Randy Barnett, director of the Center for the Constitution, which offers programs "placing special emphasis on how best to remain faithful to the Constitution's text", did not immediately respond to a request for comment Monday. "As was done for Justice Ginsburg's appearance, for instance, questions were solicited from students in advance and then the interviewer chose ones that were representative of the whole and pertinent to the event".

The students were joined by faculty members who initially took a knee and later linked arms.

Earlier, U.S. President Donald Trump called on the National Football League to ban players from kneeling in protest while the anthem is played. "And I would condemn their actions - not them as human beings - but there are many ways for these players, with all the assets they have, to express their political views other than in effect denigrating the symbols of our nation".

A spokesman for Boise State University told The Chronicle that the policy mentioned by Mr. Sessions, "specifically recognizes, in its very first section, that 'students enjoy the same freedoms of speech, peaceful assembly, and right of petition that all citizens enjoy'".

Freedom of thought and speech on the American campus are under attack.

"How is that the right way to express such a view?" he added.

But it's an important issue.

At Georgetown, the faculty, staff and students have "broad latitude to invite speakers", said Georgetown Law spokeswoman Tanya Weinberg in an emailed statement.

It seemed like they were rescinding those invites because they didn't want any sort of hostile environment, and I can understand not wanting to have a violent environment, but that's not at all what we were trying to do.